494. GIANT GASTROINTESTINAL STROMAL TUMOR OF THE ESOPHAGUS: REPORT OF TWO CASES

Abstract Gastrointestinal stromal tumor (GIST) accounts for 1-3% of all gastrointestinal tumors. Most of GIST occurs in the stomach and small intestine, but GIST from the esophagus is relatively rare at about 2-5%. Surgical resection is the treatment of choice, but no routine procedure has been established. We report two cases of esophageal GIST that underwent surgical resection. [Case 1] A 75-year-old woman. She was diagnosed with an 11 cm-sized submucosal tumor was found in the esophagus by upper gastrointestinal endoscopy. Histopathological examination showed that the tumor was GIST. The patient's postoperative course was uneventful and the patient was discharged home in good condition on the 22nd postoperative day. [Case 2] A 58-year-old man. He was diagnosed a 9 cm-sized elevated lesion in the by CECT. The tumor suspected esophageal cancer sarcoma, we underwent esophagectomy. Finally, histopathological examination revealed that the tumor was GIST. His postoperative course was uneventful and he was discharged on the 19th postoperative day. [Case 1 result] Postoperative adjuvant chemotherapy with imatinib was failed, but the follow-up period continued without recurrence. [Case2 result] Postoperative adjuvant chemotherapy with imatinib was introduced. Contrast-enhanced CT 6 months after surgery revealed multiple liver metastases. 2nd line chemotherapy with sunitinib is still ongoing. [Discussion] Surgical treatment is the first choice for esophageal GIST, but no standard surgical procedure has been established. In the past, esophagectomy similar to esophageal cancer was often performed, but thoracoscopic local resection may be selected in recent years. Even in the case of giant esophageal GIST as like this two cases, if the general condition is stable and preoperative treatment is possible, it is possible to choose to perform preoperative neoadjuvant chemotherapy.